title: Quantitative analysis of the numerical and lateral distribution of intramembrane particles in freeze-fractured biological membranes.
abstract: An improved method is presented for a quantitative analysis of freeze-fractured biological membranes. The analysis provides the numerical distribution of intramembrane particles (IMP) as a function of their diameter and a measure for the lateral IMP-distribution as a function of the IMP-diameter in terms that allow a statistical comparison between different replicas. In analyzing the lateral IMP-distribution a distinction between random, aggregative and dispersive distributions can be made for different IMP-diameter classes. Such an analysis makes the interpretation of the ultrastructural appearance of biological membranes possible in terms of the dynamic behavior of the represented membrane components. The method is demonstrated by comparing the structure of the plasma membrane of synchronized neuroblastoma cells after glutaraldehyde and formaldehyde fixation at pH 6.0.
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000648:ultrastructure*; D003584:Cytological Techniques; D005404:Fixatives; D005557:Formaldehyde; D005614:Freeze Fracturing; D005976:Glutaral; D051379:Mice; D008854:Microscopy, Electron; D009447:Neuroblastoma
chemical_list: D005404:Fixatives; D005557:Formaldehyde; D005976:Glutaral